U.S. patent number 7,381,444 [Application Number 11/449,813] was granted by the patent office on 2008-06-03 for color filter manufacturing method and apparatus, ink-jet device, color filter, display device, and apparatus having display device.
This patent grant is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Hiroshi Fujiike, Yoshihiro Shigemura, Satoshi Wada, Nobuhito Yamaguchi, Hideto Yokoi.
United States Patent |
7,381,444 |
Shigemura , et al. |
June 3, 2008 |
**Please see images for:
( Certificate of Correction ) ** |
Color filter manufacturing method and apparatus, ink-jet device,
color filter, display device, and apparatus having display
device
Abstract
A color filter manufacturing apparatus of this invention
includes a plurality of ink-jet heads (120a, 120b, 120c) each
having a first ink discharging nozzle group (108) in which the
pitch of a plurality of ink discharging nozzles in the Y-axis
direction is set to be equal to the pitch of pixels of the same
color in the Y-axis direction, and a second ink discharging nozzle
group having a nozzle pitch set to be equal to the pixel pitch in
the Y-axis direction like the first ink discharging nozzle group.
Control of an ink discharging operation is performed for only one
of the first and second ink discharging nozzle groups which is to
be used to color pixels of corresponding colors on a substrate
(1).
Inventors: |
Shigemura; Yoshihiro (Yokohama,
JP), Yamaguchi; Nobuhito (Tokyo, JP),
Yokoi; Hideto (Yokohama, JP), Wada; Satoshi
(Tokyo, JP), Fujiike; Hiroshi (Yokohama,
JP) |
Assignee: |
Canon Kabushiki Kaisha (Tokyo,
JP)
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Family
ID: |
27528629 |
Appl.
No.: |
11/449,813 |
Filed: |
June 9, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060228469 A1 |
Oct 12, 2006 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10924936 |
Aug 25, 2004 |
7270846 |
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08679979 |
Apr 5, 2005 |
6874883 |
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Foreign Application Priority Data
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Jul 19, 1995 [JP] |
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7-182560 |
Jul 26, 1995 [JP] |
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7-190091 |
Sep 4, 1995 [JP] |
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7-226443 |
Sep 14, 1995 [JP] |
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7-236781 |
Jul 4, 1996 [JP] |
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8-175189 |
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Current U.S.
Class: |
427/162; 347/22;
347/13; 347/24; 347/37; 347/40; 347/43; 427/165; 427/256; 427/287;
427/164; 347/42; 347/39; 347/30; 347/12 |
Current CPC
Class: |
B41J
2/1652 (20130101); B41J 2/21 (20130101); B41J
2/2132 (20130101); G02B 5/201 (20130101); B41J
2202/09 (20130101) |
Current International
Class: |
B05D
5/06 (20060101) |
Field of
Search: |
;427/162,164,165,256,287
;347/12,13,40,42,43,22,30,37,39 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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54-158232 |
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59-75205 |
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60-41002 |
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60-104335 |
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60-104338 |
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JP |
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63-294503 |
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Apr 1988 |
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JP |
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63-235901 |
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Sep 1988 |
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JP |
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1-217320 |
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JP |
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5-301379 |
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Nov 1993 |
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JP |
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6-198916 |
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Jul 1994 |
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JP |
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6-246931 |
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Sep 1994 |
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7-146406 |
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Jun 1995 |
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8-086913 |
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Apr 1996 |
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JP |
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8-179307 |
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Jul 1996 |
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JP |
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Primary Examiner: Bashore; Alain L.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Parent Case Text
This is a division of application Ser. No. 10/924,936, filed on
Aug. 25, 2004 now U.S. Pat. No. 7,270,846, which is a divisional of
application Ser. No. 08/679,979, filed on Jul. 15, 1996, which is
now U.S. Pat. No. 6,874,883, issued on Apr. 5, 2005.
Claims
What is claime is:
1. A method of manufacturing a color filter having a plurality of
colored pixels on a substrate by discharging an ink having a color
other than black from an ink-jet head having a plurality of ink
discharging nozzles while performing relative movement of the
ink-jet head and the substrate, comprising the steps of: dividing
the plurality of ink discharging nozzles for discharging an ink
having a same color other than black into a plurality of nozzle
groups, each of the nozzle groups comprising ink discharging
nozzles which are arrayed discontinuously; coloring the pixels of
one substrate by using only one nozzle group in the plurality of
nozzle groups for the same color; and switching from the one nozzle
group to an other nozzle group as a nozzle group to be used for the
same color, wherein an operation of the switching in said switching
step is not performed during coloring of the one substrate.
2. A method according to claim 1, further comprising the step of:
adjusting relative positions of the pixels of the substrate and the
nozzles of the other nozzle group switched by the switching
operation.
3. A method of manufacturing a liquid crystal panel having a color
filter having a plurality of colored pixels on a substrate by
discharging an ink having a color other than black from an ink-jet
head having a plurality of ink discharging nozzles while performing
relative movement of the ink-jet head and the substrate, comprising
the steps of: preparing the color filter, by: dividing the
plurality of ink discharging nozzles for discharging an ink having
a same color other than black into a plurality of nozzle groups,
each of the nozzle groups comprising ink discharging nozzles which
are arrayed discontinuously; coloring the pixels of one substrate
by using only one nozzle group in the plurality of nozzle groups
for the same color; and switching from the one nozzle group to an
other nozzle group as a nozzle group to be used for the same color,
wherein an operation of the switching in said switching step is not
performed during coloring the one substrate, and sealing a liquid
crystal compound between the prepared color filter and a counter
substrate.
4. A method of manufacturing a color filter having a plurality of
colored pixels on a substrate, comprising the steps of: performing
relative movement of the substrate and ink-jet heads corresponding
to different colors other than black, each of the ink-jet heads
having a plurality of nozzle groups corresponding to a same color,
each of the nozzle groups comprising a plurality of ink discharging
nozzles which are arrayed discontinuously; forming the colored
pixels having different colors by discharging different color inks
from respective nozzle groups for respective different colors onto
the pixels of the substrate while performing relative movement of
the substrate and the ink-jet heads a plurality of times; and
switching, for at least one of the different colors, from the one
nozzle group to an other nozzle group as a nozzle group to be used,
wherein, in coloring one substrate by plural relative movements in
said forming step, respective inks having different colors are
discharged by using only one nozzle group of respective nozzle
groups for respective different colors in the plural relative
movements, and wherein an operation of the switching in said
switching step is not performed during coloring of the one
substrate.
5. A method according to claim 4, further comprising the step of:
adjusting relative positions of the pixels of the substrate and the
nozzles of an other nozzle group.
6. A method of manufacturing a liquid crystal panel having a color
filter, comprising: preparing the color filter to have a plurality
of colored pixels on a substrate by: performing relative movement
of the substrate and ink-jet heads corresponding to different
colors other than black, each of the ink-jet heads having a
plurality of nozzle groups corresponding to a same color, each of
the nozzle groups comprising a plurality of ink discharging nozzles
which are arrayed discontinuously; forming the colored pixels
having different colors by discharging different color inks from
respective nozzle groups for respective different colors onto the
pixels of the substrate while performing relative movement of the
substrate and the ink-jet heads a plurality of times; and
switching, for at least one of the different colors, from the one
nozzle group to an other nozzle group as a nozzle group to be used,
wherein, in coloring one substrate by plural relative movements in
said forming step, respective inks having different colors are
discharged by using only one nozzle group of respective nozzle
groups for respective different colors in the plural relative
movements, and wherein an operation of the switching in said
switching step is not performed during coloring of the one
substrate, and sealing a liquid crystal compound between the color
filter and a counter substrate.
7. A method of manufacturing a color filter having a plurality of
colored pixels on a substrate by discharging an ink having a color
other than black from an ink-jet head having a plurality of ink
discharging nozzles while performing relative movement of the
ink-jet head and the substrate, comprising the steps of: dividing
the plurality of ink discharging nozzles for discharging an ink
having a same color other than black into a plurality of nozzle
groups, the plurality of nozzle groups including at least a first
nozzle group and a second nozzle group, each nozzle group
comprising ink discharging nozzles which are arrayed
discontinuously; coloring the pixels of one substrate by using only
the first nozzle group for the same color; switching from the first
nozzle group to the second nozzle group as a nozzle group to be
used for coloring the pixels; adjusting relative positions of the
pixels of the substrate and the nozzles of the second nozzle group;
and coloring the pixels of an other substrate by using only the
second nozzle group for the same color, wherein an operation of the
switching in said switching step is not performed during coloring
of the substrate.
8. A method according to claim 7, wherein the first nozzle group
corresponds to positions of the pixels of the one substrate, and
the second nozzle group does not correspond to the positions of the
pixels of the one substrate, and the first nozzle group corresponds
to positions of the pixels of the other substrate and the second
nozzle group does not correspond to the positions of the pixels of
the other substrate.
9. A method according to claim 7, wherein the nozzles of the first
nozzle group consist of every predetermined number of nozzles and
the nozzles of the second nozzle group consist of every
predetermined number of nozzles, and each of the nozzles of the
second nozzle group are arranged between the nozzles of the first
nozzle group respectively.
10. A method of manufacturing a liquid crystal panel having a color
filter having a plurality of colored pixels on a substrate by
discharging an ink having a color other than black from an ink-jet
head having a plurality of ink discharging nozzles while performing
relative movement of the ink-jet head and the substrate, comprising
the steps of: preparing the color filter by: dividing the plurality
of ink discharging nozzles for discharging an ink having a same
color other than black into a plurality of nozzle groups, the
plurality of nozzle groups including at least a first nozzle group
and a second nozzle group, each nozzle group comprising ink
discharging nozzles which are arrayed discontinuously; coloring the
pixels of one substrate by using only the first nozzle group for
the same color; switching from the first nozzle group to the second
nozzle group as a nozzle group to be used for coloring the pixels;
adjusting relative positions of the pixels of the substrate and the
nozzles of the second nozzle group; and coloring the pixels of an
other substrate by using only the second nozzle group for the same
color, wherein an operation of the switching in said switching step
is not performed during coloring of the substrate, and sealing a
liquid crystal compound between the prepared color filter and a
counter substrate.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a color filter method and
apparatus for manufacturing a color filter by forming a large
number of pixels colored in a plurality of kinds of colors on a
transparent substrate, an ink-jet device, a color filter, a display
device, and an apparatus having the display device.
2. Description of the Related Art
With recent advances in personal computers, especially portable
personal computers, the demand tends to arise for liquid crystal
displays, especially color liquid crystal displays. However, in
order to further popularize the use of liquid crystal displays, a
reduction in cost must be achieved. Especially, it is required to
reduce the cost of a color filter which occupies a large proportion
of the total cost. Various methods have been tried to satisfy the
required characteristics of color filters while meeting the above
requirements. However, any method capable of satisfying all the
requirements has not been established. The respective methods will
be described below.
The first method is a dyeing method. In the dyeing method, a
water-soluble polymer material as a dyeable material is applied to
a glass substrate, and the coating is patterned into a desired
shape by a photolithographic process. The obtained pattern is
dipped in a dye bath to obtain a colored pattern. This process is
repeated three times to form R, G, and B color filter layers.
The second method is a pigment dispersion method, which is
currently replacing the dyeing method. In this method, a
pigment-dispersed photosensitive resin layer is formed on a
substrate and patterned into a single-color pattern. This process
is repeated three times to obtain R, G, and B color filter
layers.
The third method is an electrodeposition method. In this method, a
transparent electrode is patterned on a substrate, and the
resultant structure is dipped in an electrodeposition coating fluid
containing a pigment, a resin, an electrolyte, and the like to be
colored in the first color by electrodeposition. This process is
repeated three times to form R, G, and B coatings. Thereafter, the
resin layers are thermoset to form colored layers.
The fourth method is a print method. In this method, a pigment is
dispersed in a thermosetting resin, and a print operation is
performed three times to form R, G, and B coatings separately, and
thermosetting the resins, thereby forming colored layers. In either
of the above methods, a protective layer is generally formed on the
colored layers.
The point common to these methods is that the same process must be
repeated three times to obtain layers colored in three colors,
i.e., R, G, and B. This causes an increase in cost. In addition, as
the number of processes increases, the yield decreases. In the
electrodeposition method, limitations are imposed on pattern shapes
which can be formed. For this reason, with the existing techniques,
this method cannot be applied to a TFT type color liquid display.
In the print method, a pattern with a fine pitch cannot be formed
because of poor resolution and poor evenness.
In order to eliminate these drawbacks, methods of manufacturing
color filters by an ink-jet system are disclosed in Japanese Patent
Laid-Open Nos. 59-75205, 63-235901, 63-294503, and 1-217320.
These references disclose, for example, a method of forming a color
filter by an ink-jet method, in which a light-shielding film is
formed on a transparent substrate to have opening portions with
predetermined regularity, and an ink is discharged from an ink-jet
head onto the opening portions to color the substrate.
In general, it takes much time and cost to develop an ink-jet head.
Even if a custom ink-jet head is developed for a color filter
manufacturing apparatus, since the production is smaller than that
of ink-jet heads generally used for printers and the like, the cost
of the custom ink-jet head is very high. As a result, the cost of
the manufacturing apparatus becomes high, and hence the cost of a
color filter increases.
Assume that ink-jet heads generally used for printers are applied
to the manufacture of color filters. The resolution of most of the
existing printer ink-jet heads is 300 dpi, 360 dpi, 400 dpi, 600
dpi, or 720 dpi. The pixel pitch of a color filter of a 9.4-inch
VGA type is 300 .mu.m (corresponding to 84.7 dpi). The pixel pitch
of color filters of a 10.4-inch XGA type and a 12.9-inch EWS type
is 207 .mu.m (corresponding to 122.7 dpi). The pixel pitch of color
filters of a 12.1-inch XGA type, a 13.8-inch EWS, and a 15.5-inch
EWS type is 240 .mu.m (corresponding to 105.8 dpi). There is no
combination of an ink-jet head and a color filter whose resolution
and pixel pitch match with each other or are an integral multiple.
Considering other combinations, there is hardly any combination of
an ink-jet head and a color filter whose resolution and pixel pitch
match with each other or are an integral multiple.
When, therefore, an ink-jet head used for a general ink-jet printer
is to be applied to a color filter manufacturing apparatus, the
present applicant has studied a technique of matching the
resolution of the ink-jet head with the pixel pitch of a color
filter by positioning the ink-jet head obliquely with respect to a
color filter substrate.
The present applicant has also studied a technique of mounting the
ink-jet head on the manufacturing apparatus such that the angle of
the ink-jet head can be changed with respect to the a color filter
substrate to allow the single ink-jet head to cope with the pixel
pitches of various types of color filters.
When, however, the ink-jet head is mounted obliquely with respect
to a color filter, a coloring operation is performed by relatively
scanning the ink-jet head and the color filter, a relative scanning
operation is required in excess of an amount corresponding to the
oblique positioning of the ink-jet head. This increases the
coloring time required for one substrate. Especially when an
ink-jet head shorter than the effective pixel area of a color
filter is used, since a relative scanning operation must be
performed a plurality of numbers of times, a longer coloring time
is required. With an increase in coloring time per substrate, the
production of color filters per unit time decreases, resulting in
an increase in the cost of a color filter.
In addition, when an ink-jet head to be used is caused to stand, an
ink in discharging nozzles of the ink-jet head increases its
viscosity or solidifies upon contacting air. As a result, a
discharge failure, i.e., inability to discharge the ink, or
twisting, i.e., tilting of an ink discharging direction, may occur.
For this reason, the nozzle surfaces are covered with cap members
when the ink-jet head is not used. Even with the cap members, in an
initial period of a discharging operation, first some inks to be
discharged from one nozzle may not be discharged, or twisting may
occur because of the influence of the ink whose viscosity has
increased. If the ink is discharged onto a recording medium such as
a paper sheet in this state, part of a character may be omitted or
become excessively bright or dark, resulting in a deterioration in
print quality. In order to prevent such a phenomenon, a receiving
portion for receiving the pre-discharged ink is formed in a cap
portion or the like, and several inks are preliminarily discharged
(pre-discharging operation) onto the receiving portion before an
actual printing operation is performed. This operation itself is
generally performed in an ink-jet printer, and hence is not a
special operation.
When an ink-jet head is applied to a color filter manufacturing
apparatus, unlike in a general printer, a coloring operation is
performed by discharging an ink from the ink-jet head onto opening
portions having predetermined regularity, as described above. Owing
to this method, the color filter manufacturing apparatus demands an
ink landing accuracy 10 times higher than that in the general
printer. For this reason, a pre-discharging operation becomes more
important, and it is preferable that a pre-discharging operation
always be performed before a color pattern is formed by discharging
an ink onto a glass substrate.
When the manufacturing apparatus uses a long head which can color
an entire glass substrate with one scanning operation after this
pre-discharging operation, the following problem is not posed.
When, however, the apparatus uses a short head which colors a glass
substrate with a plurality of numbers of times of scanning
operations, since the position of the head relative to the
substrate is changed between the scanning operations, an idling
time during which the discharging operation of the head is stopped
is required. If this time increases, a discharge failure or
twisting may occur in discharging the ink in the next scanning
operation.
In coloring the entire substrate surface with a plurality of
numbers of times of scanning operations, the same nozzles are not
necessarily used for each scanning operation owing to the
relationship between the number of discharging nozzles which can
used in one scanning operation, and the number of pixels
constituting a color filter. For this reason, nozzles which have
not been used in the previous scanning operation may be used.
As is apparent, since the ink in the nozzles which have not been
used in the previous scanning operation contact air without being
used for a long period of time as compared with the ink in the
remaining nozzles, the ink in the nozzles which have not been used
may increase its viscosity or solidify. For this reason, when the
ink is to be discharged from the nozzles which have not been used,
a discharge failure, i.e., inability to discharge the ink, or
twisting, i.e., tilting of an ink discharging direction, may occur.
As a result, a defective color filter may be manufactured.
In order to prevent this, the head may be relatively moved to an
ink-receiving portion for a pre-discharging operation, which is
formed in the cap portion or the like to perform a pre-discharging
operation every time a scanning operation is performed. With this
operation, however, the time required to completely color one
substrate increases, and the production per unit time decreases,
resulting in an increase in the cost of a color filter. That is,
the present applicant found this method undesirable.
In addition to the above problem, the following problem is also
posed.
Prior to a detailed description of this problem, the following case
studied by the present applicant will be described below with
reference to FIG. 1. In applying an ink-jet head used for a general
ink-jet printer to a color filter manufacturing apparatus, the
ink-jet head is mounted obliquely with respect to a color filter
substrate to match the resolution of the ink-jet head with the
pixel pitch of a color filter.
FIG. 1 is a plan view showing how the pixels of a color filter are
colored by an ink-jet head. With regard to the ink-jet head, only
the position of a nozzle array is shown in FIG. 1. In this state,
of a predetermined pattern, a portion to be colored in red is being
colored. Note that the letters R, G, and B in the respective pixels
in FIG. 1 indicate that the respective pixels are to be colored in
red (R), green (G), and blue (B).
Reference numeral 1013 denotes a nozzle array formed on the ink-jet
head. An ink is discharged from this nozzle array to form ink dots
on the substrate. Reference numeral 1014 denotes each pixel of a
color filter. On these pixels on the substrate, ink dots are
formed.
In the case shown in FIG. 1, since the pixel pitch of the color
filter does not coincide with the nozzle pitch of the ink-jet head,
the head is tilted to make the positions of every three pixels of
the same color in the Y direction coincide with the positions of
the ink discharged from every five nozzles. Ink dots are then
formed in the pixels 1014 while the ink-jet head is relatively
moved in the X direction in FIG. 1, thereby coloring the pixels.
This operation is performed using ink-jet heads for discharging
red, green, and blue inks to manufacture a color filter. In this
operation, in the ink-jet head for coloring red pixels, which is
shown in FIG. 1, the second, seventh, and twelfth nozzles are used
to discharge the ink, but the remaining nozzles are not used.
In this case, as this ink-jet head, a general ink-jet head having a
nozzle pitch of 360 dpi (70.5 .mu.m) is used. As the color filter,
a filter having a pixel pitch of 100 .mu.m is used.
This ink-jet head has the following characteristics:
(1) When a nozzle clogs with a solid matter in an ink, a normal
discharging operation may not be performed. In this case, if a
nozzle in use does not properly discharge an ink, the entire
ink-jet head is replaced.
(2) In an ink-jet system using a thermal phenomenon, in particular,
when a predetermined number of inks are discharged, the nozzle
becomes incapable of properly discharging an ink because of
scorching of the ink or the like. That is, the service life of each
nozzle depends on the number of inks discharged. For this reason,
an ink-jet head must be periodically replaced.
(3) In the ink-jet system using the thermal phenomenon, since a
heater provided for each nozzle which is discharging an ink
generates heat, repetition of a discharging operation will raise
the temperature near the nozzle. The amount of ink discharged
depends on temperatures. For this reason, ink dots gradually change
in size, and the ink-jet head expands, resulting in deformation
such as a change in nozzle pitch.
As described above, in a color filter manufacturing apparatus, if
only specific nozzles are used, the following problems are
posed:
(1) When a given nozzle becomes incapable of properly discharging
an ink, the entire ink-jet head must be replaced, although the
remaining nozzles can be used.
(2) In the ink-jet system using the thermal phenomenon, in
particular, since the service life of each nozzle depends on the
number of inks discharged, head replacement must be periodically
performed. In this replacement, the overall service life of the
ink-jet head coincides with the service life of some nozzles which
have been used, although the majority of the remaining nozzles can
be used.
(3) In the ink-jet system using the thermal phenomenon, in
particular, as a discharging operation is performed, the
temperature near each nozzle in use rises, and the amount of ink
discharged varies. For this reason, the size and color density of
ink dots formed on the substrate vary, adversely affecting the
uniformity of a color filter.
The following problem is also posed. An impurity may elute from a
coloring material contained in an ink used for a color filter into
a liquid crystal layer to cause a deterioration in display quality.
For this reason, this ink must be purified to remove such an
impurity. Consequently, the ink becomes expensive. In order to
achieve a reduction in cost, a demand has arisen for a reduction in
the amount of ink used.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the above
problems, and has as its object to provide a color filter
manufacturing method and apparatus which can decrease the cost of
an ink-jet head and the cost of the manufacturing apparatus by
using an ink-jet head used in a general printer or having a simple
structure as an ink-jet head used to manufacture a color
filter.
It is another object of the present invention to provide an
inexpensive color filter by reducing the amounts of inks used per
color filter, a display device using the color filter, and an
apparatus using the display device.
It is still another object of the present invention to provide a
color filter manufacturing method and apparatus which can stabilize
the discharging operation of an ink-jet head to suppress the
occurrence of defective products and can shorten the drawing time
required for one glass substrate and increase the production per
unit time to produce a color filter at a lower cost when one glass
substrate is to be colored by performing a scanning operation a
plurality of numbers of times, a color filter, a display device,
and an apparatus having the display device.
It is still another object of the present invention to provide a
color filter manufacturing apparatus which can shorten the idle
time between scanning operations during which each ink discharging
nozzle of an ink-jet head having ink discharging nozzles arranged
at a pitch equal to a pixel pitch discharges no ink, stabilize the
discharging operation of the ink-jet head, suppress the occurrence
of defective products, and increase the yield when a drawing
operation is to be performed for one substrate by relatively
scanning the ink-jet head a plurality of numbers of times.
It is still another object of the present invention to switch a
currently used nozzle to another nozzle of the same ink-jet
head.
It is still another object of the present invention to reduce the
frequency at which ink-jet heads are replaced owing to the service
life of each nozzle.
It is still another object of the present invention to keep the
size and color density of each ink dot constant.
In order to solve the above problems and achieve the above objects,
a color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its first
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging many pixels colored in the
same color on a substrate in an X-axis direction as one direction,
and periodically forming and arranging pixels such that pixels
adjacent to each other in a Y-axis direction perpendicular to the
X-axis direction are colored in different colors, comprising a
plurality of ink-jet heads for different colors, each having a
plurality of ink discharging nozzles arranged in the Y-axis
direction, each ink-jet head having a first ink discharging nozzle
group, in which a pitch of the plurality of ink discharging nozzles
in the Y-axis direction is set to be equal to a pitch of the pixels
of the same color in the Y-axis direction, and a second ink
discharging nozzle group having a nozzle pitch set to be equal to
the pixel pitch in the Y-axis direction like the first ink
discharging nozzle group, moving means for moving the relative
positions of the plurality of ink-jet heads and the substrate, and
control means for controlling an operation of the moving means and
ink discharging operations of the plurality of ink-jet heads,
wherein when the first ink discharging nozzle group is used to
color the pixels, the second ink discharging nozzle group is not
used to color the pixels, and the control means controls an ink
discharging operation of only a nozzle group, of the first and
second ink discharging nozzles, which is to be used to color pixels
of corresponding colors on the substrate.
A color filter manufacturing method of the present invention is
characterized by the following process according to its first
aspect.
There is provided a manufacturing method for a color filter
manufactured by forming and arranging many pixels colored in the
same color on a substrate in an X-axis direction as one direction,
and periodically forming and arranging pixels such that pixels
adjacent to each other in a Y-axis direction perpendicular to the
X-axis direction are colored in different colors, comprising the
steps of using a plurality of ink-jet heads for different colors,
each having a plurality of ink discharging nozzles arranged in the
Y-axis direction, each ink-jet head having a first ink discharging
nozzle group, in which a pitch of the plurality of ink discharging
nozzles in the Y-axis direction is set to be equal to a pitch of
the pixels of the same color in the Y-axis direction, and a second
ink discharging nozzle group having a nozzle pitch set to be equal
to the pixel pitch in the Y-axis direction like the first ink
discharging nozzle group, moving means for moving the relative
positions of the plurality of ink-jet heads and the substrate, and
control means for controlling an operation of the moving means and
ink discharging operations of the plurality of ink-jet heads, the
second ink discharging nozzle group for coloring of the pixels
being not used when the first ink discharging nozzle group is used
to color the pixels, and the control means controlling an ink
discharging operation of only a nozzle group, of the first and
second ink discharging nozzles, which is to be used to color pixels
of corresponding colors on the transparent substrate, and causing
each of the ink-jet heads to discharge an ink while scanning the
ink-jet head in the X-axis direction, and coloring all the pixels
by scanning the ink-jet head once or a plurality of numbers of
times in the X-axis direction.
A color filter of the present invention is characterized by the
following arrangement according to its first aspect.
There is provided a color filter manufactured by forming and
arranging many pixels colored in the same color on a substrate in
an X-axis direction as one direction, and forming and arranging
pixels such that pixels adjacent to each other in a Y-axis
direction perpendicular to the X-axis direction are colored in
different colors, wherein the color filter is manufactured by using
a plurality of ink-jet heads for different colors, each having a
plurality of ink discharging nozzles arranged in the Y-axis
direction, each ink-jet head having a first ink discharging nozzle
group, in which a pitch of the plurality of ink discharging nozzles
in the Y-axis direction is set to be equal to a pitch of the pixels
of the same color in the Y-axis direction, and a second ink
discharging nozzle group having a nozzle pitch set to be equal to
the pixel pitch in the Y-axis direction like the first ink
discharging nozzle group, moving means for moving the relative
positions of the plurality of ink-jet heads and the substrate, and
control means for controlling an operation of the moving means and
ink discharging operations of the plurality of ink-jet heads, and
causing each of the ink-jet heads to discharge an ink while
scanning the ink-jet head in the X-axis direction, and coloring all
the pixels by scanning the ink-jet head once or a plurality of
numbers of times in the X-axis direction.
A display device of the present invention is characterized by the
following arrangement according to its first aspect.
There is provided a display device using a color filter
manufactured by forming and arranging many pixels colored in the
same color on a substrate in an X-axis direction as one direction,
and periodically forming and arranging pixels such that pixels
adjacent to each other in a Y-axis direction perpendicular to the
X-axis direction are colored in different colors, integrally
comprising a color filter manufactured by using a plurality of
ink-jet heads for different colors, each having a plurality of ink
discharging nozzles arranged in the Y-axis direction, each ink-jet
head having a first ink discharging nozzle group, in which a pitch
of the plurality of ink discharging nozzles in the Y-axis direction
is set to be equal to a pitch of the pixels of the same color in
the Y-axis direction, and a second ink discharging nozzle group
having a nozzle pitch set to be equal to the pixel pitch in the
Y-axis direction like the first ink discharging nozzle group,
moving means for moving the relative positions of the plurality of
ink-jet heads and the substrate, and control means for controlling
an operation of the moving means and ink discharging operations of
the plurality of ink-jet heads, and causing each of the ink-jet
heads to discharge an ink while scanning the ink-jet head in the
X-axis direction, and coloring all the pixels by scanning the
ink-jet head once or a plurality of numbers of times in the X-axis
direction, and light amount changing means for changing a light
amount.
An apparatus including a display device of the present invention is
characterized by the following arrangement according to its first
aspect.
There is provided an apparatus having a display device using a
color filter manufactured by forming and arranging many pixels
colored in the same color on a substrate in an X-axis direction as
one direction, and periodically forming and arranging pixels such
that pixels adjacent to each other in a Y-axis direction
perpendicular to the X-axis direction are colored in different
colors, integrally comprising a display device integrally having a
color filter manufactured by using a plurality of ink-jet heads for
different colors, each having a plurality of ink discharging
nozzles arranged in the Y-axis direction, each ink-jet head having
a first ink discharging nozzle group, in which a pitch of the
plurality of ink discharging nozzles in the Y-axis direction is set
to be equal to a pitch of the pixels of the same color in the
Y-axis direction, and a second ink discharging nozzle group having
a nozzle pitch set to be equal to the pixel pitch in the Y-axis
direction like the first ink discharging nozzle group, moving means
for moving the relative positions of the plurality of ink-jet heads
and the substrate, and control means for controlling an operation
of the moving means and ink discharging operations of the plurality
of ink-jet heads, and causing each of the ink-jet heads to
discharge an ink while scanning the ink-jet head in the X-axis
direction, and coloring all the pixels by scanning the ink-jet head
once or a plurality of numbers of times in the X-axis direction,
and light amount changing means for changing a light amount, and
image signal supply means for supplying an image signal to the
display device.
An ink-jet apparatus of the present invention is characterized by
the following arrangement.
There is provided an ink-jet apparatus for coloring a coloring
medium by using a first ink discharging nozzle group, and a second
ink discharging nozzle group capable of discharging an ink in place
of the first ink discharging nozzle, comprising control means for
causing only the first ink discharging nozzle group to perform a
pre-discharging operation before the coloring medium is colored by
the first ink discharging nozzle group, and causing both the first
and second ink discharging nozzle groups to perform a
pre-discharging operation at a frequency lower than that of a
pre-discharging operation performed by the first ink discharging
nozzle group.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its second
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging a plurality of colored pixels
on a substrate, comprising an ink-jet head having a plurality of
ink discharging nozzles, moving means for moving relative positions
of the ink-jet head and the substrate, and control means for
controlling an operation of the moving means and an ink discharging
operation of the ink-jet head, wherein when the ink-jet head is to
be scanned a plurality of numbers of times so as to color the
substrate, the control means controls an ink discharging operation
such that ink discharging nozzles which have been used in a
previous scanning operation are always used entirely or partly in a
succeeding scanning operation.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its third
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging a plurality of colored pixels
on a substrate, comprising a plurality of ink-jet heads for
different colors, each having a plurality of ink discharging
nozzles, moving means for moving relative positions of the
plurality of ink-jet heads and the substrate, and control means for
controlling an operation of the moving means and ink discharging
operations of the ink-jet head, wherein when the plurality of
ink-jet heads are to be scanned a plurality of numbers of times so
as to color an entire area of the substrate, the control means
controls an ink discharging operation such that ink discharging
nozzles which have been used in a previous scanning operation are
always used entirely or partly in a succeeding scanning
operation.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its fourth
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging many pixels colored in the
same color on a substrate in an X-axis direction as one direction,
and periodically forming and arranging pixels such that pixels
adjacent to each other in a Y-axis direction perpendicular to the
X-axis direction are colored in different colors, comprising a
plurality of ink-jet heads for different colors, each having a
plurality of ink discharging nozzles arranged in the Y-axis
direction, moving means for moving relative positions of the
plurality of ink-jet heads and the substrate, and control means for
controlling an operation of the moving means and ink discharging
operations of the ink-jet head, wherein when the plurality of
ink-jet heads are to be scanned a plurality of numbers of times so
as to color an entire area of the substrate, the control means
controls an ink discharging operation such that ink discharging
nozzles which have been used in a previous scanning operation are
always used entirely or partly in a succeeding scanning
operation.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its fifth
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging many pixels colored in the
same color on a substrate in an X-axis direction as one direction,
and forming and arranging pixels such that pixels adjacent to each
other in a Y-axis direction perpendicular to the X-axis direction
are colored in different colors, comprising a plurality of ink-jet
heads for different colors, each having a plurality of ink
discharging nozzles arranged in the Y-axis direction, the ink
discharging nozzles being arranged at a pitch in the Y-axis
direction which is equal to a pitch of pixels of the same color in
the Y-axis direction, moving means for moving relative positions of
the plurality of ink-jet heads and the substrate, and control means
for controlling an operation of the moving means and ink
discharging operations of the ink-jet head, wherein when the
plurality of ink-jet heads are to be scanned a plurality of numbers
of times so as to color an entire area of the substrate, the
control means controls an ink discharging operation such that ink
discharging nozzles which have been used in a previous scanning
operation are always used entirely or partly in a succeeding
scanning operation.
A color filter manufacturing method of the present invention is
characterized by the following process according to its second
aspect.
There is provided a method of manufacturing a color filter by
arranging a plurality of colored pixels on a substrate by
controlling relative positions of an ink-jet head having a
plurality of ink discharging nozzles and the substrate, and
discharging an ink from the ink-jet head onto the substrate,
comprising in coloring an entire area of the substrate by scanning
the ink-jet head a plurality of numbers of times, performing an ink
discharging operation such that ink discharging nozzles which have
been used in a previous scanning operation are always used entirely
or partly in a succeeding scanning operation.
A color filter of the present invention is characterized by the
following arrangement according to its second aspect.
There is provided a color filter manufactured by forming and
arranging a plurality of colored pixels on a substrate, wherein the
color filter is manufactured by using an ink-jet head having a
plurality of ink discharging nozzles, moving means for moving
relative positions of the ink-jet head and the substrate, and
control means for controlling an operation of the moving means and
an ink discharging operation of the ink-jet head, and performing an
ink discharging operation such that ink discharging nozzles which
have been used in a previous scanning operation are always used
entirely or partly in a succeeding scanning operation, in coloring
an entire area of the substrate by scanning the ink-jet head a
plurality of numbers of times.
A display device of the present invention is characterized by the
following arrangement according to its second aspect.
There is provided a display device using a color filter
manufactured by forming and arranging a plurality of colored pixels
on a substrate, integrally comprising a color filter is
manufactured by using an ink-jet head having a plurality of ink
discharging nozzles, moving means for moving relative positions of
the ink-jet head and the substrate, and control means for
controlling an operation of the moving means and an ink discharging
operation of the ink-jet head, and performing an ink discharging
operation such that ink discharging nozzles which have been used in
a previous scanning operation are always used entirely or partly in
a succeeding scanning operation, in coloring an entire area of the
substrate by scanning the ink-jet head a plurality of numbers of
times, and light amount changing means for changing a light
amount.
An apparatus including a display device of the present invention is
characterized by the following arrangement according to its second
aspect.
There is provided an apparatus having a display device using a
color filter manufactured by forming and arranging a plurality of
colored pixels on a substrate, comprising a display device
integrally having a color filter is manufactured by using an
ink-jet head having a plurality of ink discharging nozzles, moving
means for moving relative positions of the ink-jet head and the
substrate, and control means for controlling an operation of the
moving means and an ink discharging operation of the ink-jet head,
and performing an ink discharging operation such that ink
discharging nozzles which have been used in a previous scanning
operation are always used entirely or partly in a succeeding
scanning operation, in coloring an entire area of the substrate by
scanning the ink-jet head a plurality of numbers of times, and
light amount changing means for changing a light amount, and image
signal output means for outputting an image signal to the display
device.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its sixth
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging many colored pixels on a
substrate, comprising ink discharging means having a plurality of
ink discharging nozzles, moving means for moving relative positions
of the ink discharging means and the substrate, and control means
for controlling an operation of the moving means and an ink
discharging operation of the ink discharging means, wherein when
the ink discharging means is to be scanned a plurality of numbers
of times to color the substrate, the control means controls such
that the numbers of nozzles used for coloring in the respective
scanning operations become substantially equal to each other.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its seventh
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging many colored pixels on a
substrate, comprising a plurality of ink discharging means for
different colors, each having a plurality of ink discharging
nozzles, moving means for moving relative positions of the
plurality of ink discharging means and the substrate, and control
means for controlling an operation of the moving means and ink
discharging operations of the plurality of ink discharging means,
wherein when the plurality of ink discharging means are to be
scanned a plurality of numbers of times to color an entire area of
the substrate, the control means controls such that the numbers of
nozzles used for coloring in the respective scanning operations
become substantially equal to each other.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its eight
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging many pixels colored in the
same color on a substrate in an X-axis direction as one direction,
and forming and arranging pixels such that pixels adjacent to each
other in a Y-axis direction perpendicular to the X-axis direction
are colored in different colors, comprising a plurality of ink
discharging means for different colors, each having a plurality of
ink discharging nozzles arranged in the Y-axis direction, moving
means for moving relative positions of the plurality of ink
discharging means and the substrate, and control means for
controlling an operation of the moving means and ink discharging
operations of the plurality of ink discharging means, wherein when
the plurality of ink discharging means are to be scanned a
plurality of numbers of times to color an entire area of the
substrate, the control means controls such that the numbers of
nozzles used for coloring in the respective scanning operations
become substantially equal to each other.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its ninth
aspect.
There is provided a manufacturing apparatus for a color filter
manufactured by forming and arranging many pixels colored in the
same color on a substrate in an X-axis direction as one direction,
and forming and arranging pixels such that pixels adjacent to each
other in a Y-axis direction perpendicular to the X-axis direction
are colored in different colors, comprising a plurality of ink
discharging means for different colors, each having a plurality of
ink discharging nozzles arranged in the Y-axis direction, the ink
discharging means having nozzle arrays in which at least a pitch of
the plurality of ink discharging nozzles in the Y-axis direction is
set to be equal to a pitch of pixels of the same color in the
Y-axis direction, moving means for moving relative positions of the
plurality of ink discharging means and the substrate, and control
means for controlling an operation of the moving means and ink
discharging operations of the plurality of ink discharging means,
wherein when the plurality of ink discharging means are to be
scanned a plurality of numbers of times to color an entire area of
the substrate, the control means controls such that the numbers of
nozzles used for coloring in the respective scanning operations
become substantially equal to each other.
A color filter manufacturing method of the present invention is
characterized by the following process according to its third
aspect.
There is provided a manufacturing method for a color filter
manufactured by forming and arranging many colored pixels on a
substrate, comprising in coloring an entire area of the substrate
by performing a scanning operation of moving relative positions of
an ink discharging means having a plurality of ink discharging
nozzles and the substrate a plurality of numbers of times,
performing a coloring operation such that the numbers of nozzles
used for coloring in the respective scanning operations become
substantially equal to each other.
A color filter of the present invention is characterized by the
following arrangement according to its third aspect.
There is provided a color filter manufactured by forming and
arranging many colored pixels on a substrate, wherein when an
entire area of the substrate is to be colored by performing a
scanning operation of moving relative positions of an ink
discharging means having a plurality of ink discharging nozzles and
the substrate a plurality of numbers of times, a coloring operation
is performed such that the numbers of nozzles used for coloring in
the respective scanning operations become substantially equal to
each other.
A display device of the present invention is characterized by the
following arrangement according to its third aspect.
There is provided a display device using a color filter
manufactured by forming and arranging many colored pixels on a
substrate, integrally comprising a color filter manufactured by
performing a coloring operation such that the numbers of nozzles
used for coloring in the respective scanning operations become
substantially equal to each other when an entire area of the
substrate is to be colored by performing a scanning operation of
moving relative positions of an ink discharging means having a
plurality of ink discharging nozzles and the substrate a plurality
of numbers of times, and light amount changing means for changing a
light amount.
An apparatus including a display device of the present invention is
characterized by the following arrangement according to its third
aspect.
There is provided an apparatus having a display device using a
color filter manufactured by forming and arranging many colored
pixels on a substrate, comprising a display device integrally
having a color filter manufactured by performing a coloring
operation such that the numbers of nozzles used for coloring in the
respective scanning operations become substantially equal to each
other when an entire area of the substrate is to be colored by
performing a scanning operation of moving relative positions of an
ink discharging means having a plurality of ink discharging nozzles
and the substrate a plurality of numbers of times, and light amount
changing means for changing a light amount, and image signal output
means for outputting an image signal to the display device.
A color filter manufacturing method of the present invention is
characterized by the following process according to its fourth
aspect.
There is provided a color filter manufacturing method of dividing
all ink discharging nozzles of an ink-jet head having the plurality
of ink discharging nozzles into a plurality of nozzle groups each
including a predetermined number of nozzles, discharging an ink
upon switching the plurality of nozzle groups as needed, and
coloring each pixel of a color filter, comprising the switching
step of switching the plurality of nozzle groups, and the
compensation step of compensating for a positional offset between a
nozzle group to be used and each pixel.
A color filter manufacturing apparatus of the present invention is
characterized by the following arrangement according to its tenth
aspect.
There is provided a color filter manufacturing apparatus for
dividing all ink discharging nozzles of an ink-jet head having the
plurality of ink discharging nozzles into a plurality of nozzle
groups each including a predetermined number of nozzles,
discharging an ink upon switching the plurality of nozzle groups as
needed, and coloring each pixel of a color filter, comprising
switching means for switching the plurality of nozzle groups,
control means for controlling a switching operation of the
switching means, and compensation means for, when the nozzle groups
are switched by the switching means, compensating for a positional
offset between the nozzle group to be used and each pixel.
Other objects and advantages besides those discussed above shall be
apparent to those skilled in the art from the description of a
preferred embodiment of the invention which follows. In the
description, reference is made to accompanying drawings, which form
a part hereof, and which illustrate an example of the invention.
Such example, however, is not exhaustive of the various embodiments
of the invention, and therefore reference is made to the claims
which follow the description for determining the scope of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing the relationship between a color filter
and an ink-jet head in a color manufacturing apparatus;
FIGS. 2A to 2F are sectional views for explaining a color filter
manufacturing process;
FIGS. 3A to 3F are sectional views for explaining another color
filter manufacturing process;
FIG. 4 is a sectional view showing the structure of a TFT liquid
crystal panel incorporating a color filter manufactured by a
manufacturing apparatus of an embodiment of the present
invention;
FIG. 5 is a sectional view showing the structure of a TFT liquid
crystal panel incorporating a color filter manufactured by the
manufacturing apparatus of an embodiment of the present
invention;
FIG. 6 is a block diagram showing an information processing
apparatus using a liquid crystal panel;
FIG. 7 is a perspective view showing the information processing
apparatus using the liquid crystal panel;
FIG. 8 is a perspective view showing an information processing
apparatus using a liquid crystal panel;
FIG. 9 is a view showing the pattern of a color filter manufactured
by the manufacturing apparatus of the embodiment;
FIG. 10 is a view showing the size of the display unit of a TFT
liquid crystal panel incorporating a color filter manufactured by
the manufacturing apparatus of the embodiment;
FIG. 11 is a perspective view showing the structure of an ink-jet
head;
FIG. 12 is a view showing the arrangement of a restoring unit for
the manufacturing apparatus of the embodiment;
FIG. 13 is a view showing a state wherein the restoring unit for
the manufacturing apparatus of the embodiment is performing a
capping operation;
FIG. 14 is a view showing a state wherein the restoring unit for
the manufacturing apparatus of the embodiment is performing a
wiping operation;
FIG. 15 is a perspective view showing the structure of an ink-jet
head;
FIG. 16 is a block diagram showing the schematic arrangement of the
manufacturing apparatus of the embodiment;
FIG. 17 is a flow chart schematically showing the operation of the
manufacturing apparatus of the embodiment;
FIG. 18 is a view showing how ink-jet heads are moved relative to a
glass substrate in the manufacturing apparatus of the
embodiment;
FIG. 19 is a view showing the positional relationship between each
pixel and each discharging nozzle in the manufacturing apparatus of
the embodiment;
FIG. 20 is a view showing how ink-jet head discharges an ink;
FIG. 21 is a view showing the arrangement of the discharging
nozzles on the nozzle surface of an ink-jet head;
FIG. 22 is a view showing the arrangement of the discharging
nozzles on the nozzle surface of an ink-jet head;
FIG. 23 is a view showing how ink-jet heads are moved relative to a
glass substrate in a manufacturing apparatus of another
embodiment;
FIG. 24 is a view showing how ink-jet heads are moved relative to a
glass substrate in a manufacturing apparatus of still another
embodiment;
FIG. 25 is a view showing the arrangement of a color filter
manufacturing apparatus of the fifth embodiment of the present
invention;
FIG. 26 is a view showing the arrangement of a color filter
manufacturing apparatus of the sixth embodiment of the present
invention; and
FIG. 27 is a view showing the arrangement of a color filter
manufacturing apparatus of the seventh embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will be
described in detail below with reference to the accompanying
drawings.
First Embodiment
FIGS. 2A to 2F show a color filter manufacturing process using a
color filter manufacturing apparatus according to an embodiment of
the present invention.
In this embodiment, as a substrate 1, a glass substrate is
generally used. However, a substrate other than a glass substrate
can be used as long as it has characteristics required for a liquid
crystal color filter, e.g., good transparency and high mechanical
strength.
First of all, the glass substrate 1 is prepared, on which a black
matrix 2 is formed to clearly partition off each pixel of a color
filter so as to obtain a clear image (FIG. 2A). As a method of
forming a black matrix, a method of forming a thin metal film on a
substrate by sputtering or deposition, and patterning the film by a
photolithographic process is available.
As shown in FIG. 2B, a coating material is applied to the substrate
1, on which the black matrix 2 is formed. The resultant structure
is pre-baked, as needed, to form a resin composition layer 3. Upon
irradiation of light or irradiation of light and a heat treatment,
the ink absorption property of the irradiated portions of the resin
composition layer 3 improves. As the coating material, the
following resin composition is used. Upon exposure or exposure and
a heat treatment, the ink absorption property of the exposed
portions of the resin composition improves. By using the difference
in ink absorption property between the exposed and non-exposed
portions, color mixing of inks and the unnecessary diffusion of an
ink can be prevented.
Pattern exposure is performed, via a mask 4, with respect to the
coating material on the portions which are not light-shielded by
the black matrix 2 to perform an ink affinity process (FIG. 2C),
thereby forming a latent image (FIG. 2D).
Subsequently, ink-jet heads are used to discharge R (red), G
(green), and B (blue) inks onto portions 6 having affinities for
inks (FIG. 2E), and the inks are dried, as needed.
Irradiation of light or a heat treatment and irradiation of light
are performed to cure the colored coating material, and a
protective layer 8 is formed as needed (FIG. 2F). The protective
layer 8 can be made of, e.g., a resin material of a photo-setting
type, thermosetting type, or photo-setting/thermosetting type, or
an inorganic film formed by deposition or sputtering. The resultant
layer needs to have transparency upon formation of a color filter
and be sufficiently resistant to the subsequent processes such as
an ITO (Indium Tin Oxide) formation process and an aligning film
formation process.
FIGS. 3A to 3F are views showing another color filter manufacturing
process.
FIG. 3A shows a glass substrate 1 having a black matrix 2
constituted by light-transmitting portions 7 and light-shielding
portions. First of all, the glass substrate 1, on which the black
matrix 2 is formed, is coated with a resin composition which can be
cured upon irradiation of light or irradiation of light and
heating, and exhibits ink receptivity. The resultant structure is
pre-baked, as needed, to form a resin composition layer 3' (FIG.
3B). The resin composition layer 3' can be formed by a coating
method such as spin coating, roller coating, bar coating, spraying,
or dipping. However, a coating method to be used is not
specifically limited.
Subsequently, pattern exposure is performed by using a photomask 4'
with respect to the resin layer portions which are light-shielded
by the black matrix 2 to partly cure the resin layer, thereby
forming portions 5' (non-colored portions) which do not absorb an
ink (FIG. 3C). Thereafter, the resin layer is colored in R, G, and
B at once by using the ink-jet heads (FIG. 3D), and the inks are
dried, as needed.
As the photomask 4' used when pattern exposure is performed, a mask
having opening portions for curing the portions light-shielded by
the black matrix is used. In this case, in order to prevent a color
omission of the color material at a portion in contact with the
black matrix, a relatively large amount of ink must be discharged.
For this reason, a mask having opening portions each having a size
smaller than the width of each light-shielding portion of the black
matrix.
As an ink to be used for a coloring operation, either of dye and
pigment inks can be used, and either of liquid and solid inks can
be used.
As a curable resin composition to be used in the present invention,
any resin composition which has ink receptivity and can be cured by
at least one of the following treatments: irradiation of light and
a combination of irradiation of light and heating, can be used. As
resins, acrylic resin, epoxy resin, and silicone resin are
available. As cellulose derivatives, hydroxypropyl cellulose,
hydroxy ethyl cellulose, methyl cellulose, carboxymethyl cellulose
are available, and modified materials are available.
Optical initiators (crosslinkers) can also be used to make
crosslinking reactions of these resins proceed upon irradiation of
light or irradiation of light and heat. As optical initiators,
dichromate, a bis-azide compound, a radical-based initiator, a
cation-based initiator, an anion-based initiator, and the like can
be used. Mixtures of these optical initiators and combinations of
the initiators and sensitizers can also be used. In addition, an
optical acid generating agent such as onium salt can be used as a
crosslinker. In order to make a crosslinking reaction further
proceed, a heat treatment may be performed after irradiation of
light.
Resin layers containing these compositions have excellent heat
resistance, excellent water resistance, and the like, and are
sufficiently resistant to high temperatures and cleaning in the
subsequent steps.
As an ink-jet system used in the present invention, a bubble-jet
type using an electrothermal converter as an energy generating
element, a piezoelectric jet type using a piezoelectric element, or
the like can be used. A coloring area and coloring pattern can be
arbitrarily set.
This embodiment exemplifies the structure in which the black matrix
is formed on the substrate. However, after a curable resin
composition layer is formed or after coloring is performed, a black
matrix may be formed on the resin layer without posing any problem.
That is, the form of a black matrix is not limited to that in this
embodiment. As a method of forming a black matrix, a method of
forming a thin metal film on a substrate by sputtering or
deposition, and patterning the film by a photolithographic process
is preferably used. However, the present invention is not limited
to this.
Subsequently, the curable resin composition is cured by performing
only one of the following treatments: irradiation of light, a heat
treatment, and a combination of irradiation of light and a heat
treatment (FIG. 3E), and a protective layer 8 is formed, as needed
(FIG. 3F). Note that reference symbol h.nu. denotes the intensity
of light. When a heat treatment is to be performed, heat is applied
instead of h.nu.. The protective layer 8 can be made of a second
resin composition of a photo-setting type, thermosetting type, or
photo-setting/thermosetting type. The resultant layer needs to have
transparency upon formation of a color filter and be sufficiently
resistant to the subsequent processes such as an ITO formation
process and an aligning film formation process.
FIGS. 4 and 5 are sectional views each showing a TFT (Thin Film
Transistor) color liquid crystal panel incorporating the color
filter of this embodiment. Note that the form of a color liquid
crystal panel is not limited to any of these examples.
In general, a color liquid crystal panel is formed by joining a
color filter substrate 1 to a counter substrate 254 and sealing a
liquid crystal compound 252 therebetween. TFTs (Thin Film
Transistors) (not shown) and transparent pixel electrodes 253 are
formed on the inner surface of one substrate 254 of the liquid
crystal panel in a matrix form. A color filter 10 is placed on the
inner surface of the other substrate 12 such that the R, G, and B
coloring materials are positioned to oppose the pixel electrodes. A
transparent counter electrode (common electrode) 250 is formed on
the entire surface of the color filter 10. A black matrix 2 is
generally formed on the color filter substrate 1 side (see FIG. 4).
However, in a BM (Black Matrix) on-array type liquid crystal panel,
the black matrix is formed on the TFT substrate side opposing the
color filter substrate (see FIG. 5). In addition, aligning films
251 are formed within the planes of the two substrates. By
performing a rubbing process for the aligning films 251, the liquid
crystal molecules can be aligned in a predetermined direction.
Polarizing plates 255 are bonded to the outer surface of the
respective glass substrates. The liquid crystal compound 252 is
filled in the gap (about 2 to 5 .mu.m) between these glass
substrates. As a blacklight, a combination of a fluorescent lamp
(not shown) and a scattering plate (not shown) is generally used. A
display operation is performed by causing the liquid crystal
compound to serve as an optical shutter for changing the
transmittance for light emitted from the backlight.
A case wherein the above liquid crystal display device is applied
to an information processing apparatus will be described below with
reference to FIGS. 6 to 8.
FIG. 6 is a block diagram showing the schematic arrangement of an
information processing apparatus serving as a wordprocessor, a
personal computer, a facsimile apparatus, and a copying machine, to
which the above liquid crystal display device is applied.
Referring to FIG. 6, reference numeral 1801 denotes a control unit
for controlling the overall apparatus. The control unit 1801
includes a CPU such as a microprocessor and various I/O ports, and
performs control by outputting/inputting control signals, data
signals, and the like to/from the respective units. Reference
numeral 1802 denotes a display unit for displaying various menus,
document information, and image data read by an image reader 1807,
and the like on the display screen; 1803, a transparent,
pressure-sensitive touch panel mounted on the display unit 1802. By
pressing the surface of the touch panel 1803 with a finger of the
user or the like, an item input operation, a coordinate position
input operation, or the like can be performed on the display unit
1802.
Reference numeral 1804 denotes an FM (Frequency Modulation) sound
source unit for storing music information, created by a music
editor or the like, in a memory unit 1810 or an external memory
unit 1812 as digital data, and reading out the information from
such a memory, thereby performing FM modulation of the information.
An electrical signal from the FM sound source unit 1804 is
converted into an audible sound by a speaker unit 1805. A printer
unit 1806 is used as an output terminal for the wordprocessor, the
personal computer, the facsimile apparatus, and the copying
machine.
Reference numeral 1807 denotes an image reader unit for
photoelectrically reading original data. The image reader unit 1807
is arranged midway along the original convey passage and designed
to read originals for facsimile and copy operations and other
various originals.
Reference numeral 1808 denotes a transmission/reception unit for
the facsimile (FAX) apparatus. The transmission/reception unit 1808
transmits original data read by the image reader unit 1807 by
facsimile, and receives and decodes a sent facsimile signal. The
transmission/reception unit 1808 has an interface function for
external units. Reference numeral 1809 denotes a telephone unit
having a general telephone function and various telephone functions
such as an answering function.
Reference numeral 1810 denotes a memory unit including a ROM for
storing system programs, manager programs, application programs,
fonts, and dictionaries, a RAM for storing an application program
loaded from the external memory unit 1812 and document information,
a video RAM, and the like.
Reference numeral 1811 denotes a keyboard unit for inputting
document information and various commands.
Reference numeral 1812 denotes an external memory unit using a
floppy disk, a hard disk, and the like. The external memory unit
1812 serves to store document information, music and speech
information, application programs of the user, and the like.
FIG. 7 is a perspective view of the information processing
apparatus in FIG. 6.
Referring to FIG. 7, reference numeral 1901 denotes a flat panel
display using the above liquid crystal display device, which
displays various menus, graphic pattern information, document
information, and the like. A coordinate input or item designation
input operation can be performed on the flat panel display 1901 by
pressing the surface of the touch panel 1803 with a finger of the
user or the like. Reference numeral 1902 denotes a handset used
when the apparatus is used as a telephone set. A keyboard 1903 is
detachably connected to the main body via a cord and is used to
perform various document functions and input various data. This
keyboard 1903 has various function keys 1904. Reference numeral
1905 denotes an insertion port through which a floppy disk is
inserted into the external memory unit 1812.
Reference numeral 1906 denotes an original table on which an
original to be read by the image reader unit 1807 is placed. The
read original is discharged from the rear portion of the apparatus.
In a facsimile receiving operation or the like, received data is
printed out by an ink-jet printer 1907.
When the above information processing apparatus is to serve as a
personal computer or a wordprocessor, various kinds of information
input through the keyboard unit 1811 are processed by the control
unit 1801 in accordance with a predetermined program, and the
resultant information is output, as an image, to the printer unit
1806.
When the information processing apparatus is to serve as the
receiver of the facsimile apparatus, facsimile information input
through the transmission/reception unit 1808 via a communication
line is subjected to reception processing in the control unit 1801
in accordance with a predetermined program, and the resultant
information is output, as a received image, to the printer unit
1806.
When the information processing apparatus is to serve as the
copying machine, an original is read by the image reader unit 1807,
and the read original data is output, as an image to be copied, to
the printer unit 1806 via the control unit 1801. Note that when the
information processing apparatus is to serve as the receiver of the
facsimile apparatus, original data read by the image reader unit
1807 is subjected to transmission processing in the control unit
1801 in accordance with a predetermined program, and the resultant
data is transmitted to a communication line via the
transmission/reception unit 1808.
Note that the above information processing apparatus may be
designed as an integrated apparatus incorporating an ink-jet
printer in the main body, as shown in FIG. 8. In this case, the
portability of the apparatus can be improved. The same reference
numerals in FIG. 8 denote parts having the same functions as those
in FIG. 7.
FIG. 9 shows the color pattern of a color filter manufactured by
the color filter manufacturing apparatus of this embodiment. Each
of the portions colored by R, G, and B inks is a pixel, which has
an almost rectangular shape. Assume that the longitudinal direction
of one pixel is the X direction, and a direction perpendicular to
the X direction is the Y direction. All the pixels have the same
size, i.e., 150 .mu.m.times.60 .mu.m. The pitch in the X direction
is 300 .mu.m, and the pitch in the Y direction is 100 g m. Pixels
of the same color are arranged in a row in the X direction, and
pixels are arranged in the Y direction such that adjacent pixels
have different colors. The pattern shown in FIG. 9 corresponds to
the pattern of the black matrix formed in the step shown in FIG.
2A.
The number of pixels in the X direction is 480, and that in the Y
direction is 1,920 (640 pixels of each color). As shown in FIG. 10,
the screen of the color filter has a size of 144 mm.times.192 mm,
which corresponds to a 9.4-inch liquid crystal panel having a
diagonal length of 240 mm.
FIG. 11 shows the arrangement of a manufacturing apparatus for
manufacturing the color filter in FIG. 9.
Referring to FIG. 11, a manufacturing apparatus 20 comprises an X-Y
table 22 mounted on a base (not shown) and capable of moving in the
X and Y directions in FIG. 11, and an ink-jet head IJH fixed on the
base via a support member (not shown) above the X-Y table 22. A
glass substrate 1 on which a black matrix 2 and a resin composition
layer 3 are formed in advance by the above method is placed on the
X-Y table 22. The ink-jet head IJH includes a red head 120a for
discharging a red ink, a green head 120b for discharging a green
ink, and a blue head 120c for discharging a blue ink. These heads
120a, 120b, and 120c are designed to discharge inks
independently.
A restoring unit 30 for performing a restoring operation for the
ink-jet head IJH is provided on an end portion of the X-Y table 22
to be movable in the Z direction with respect to the X-Y table
22.
The restoring unit 30 has a function of preventing clogging of each
nozzle of the ink-jet head IJH and removing an ink or dust adhering
to each nozzle surface of the ink-jet head IJH to always allow a
proper ink discharging operation, and a function of preventing the
manufacture of a defective product by preventing dust adhering to
each nozzle surface from falling onto a glass substrate during a
coloring operation. FIG. 12 shows the arrangement of the restoring
unit 30.
Reference numerals 31a, 31b, and 31c denote caps corresponding to
the red, green, and blue heads 120a, 120b, and 120c of the ink-jet
head IJH. While the ink-jet heads 120a, 120b, and 120c are not
performing color filter coloring operations with respect to the
glass substrate 1, the caps 31a, 31b, and 31c respectively cover
the nozzle surfaces of the ink-jet heads 120a, 120b, and 120c to
prevent the heads from being incapable of discharging the inks.
Assume that the discharging operations of the ink-jet heads 120a,
120b, and 120c are resumed after a predetermined idle time. In this
case, even if the above caps 31a, 31b, and 31c are used, owing to
the influence of an increase in the viscosity of each ink, a
discharge failure or twisting may occur in discharging first some
inks. That is, first some inks to be discharged from one nozzle may
not be discharged or may curve through the air. In this case, after
not less than a predetermined amount of ink is discharged, a normal
state is restored, and the ink is discharged straight. If such a
failure occurs while the glass substrate 1 is colored, some pixels
cannot be colored, or the ink does not land at correct positions,
resulting in a defective product. In order to prevent such a
phenomenon, a predetermined amount of ink is discharged from each
head, i.e., a pre-discharging operation is performed, before the
glass substrate 1 is colored.
In this embodiment, this pre-discharging operation is performed by
using the caps. However, dedicated ink-receiving portions for
pre-discharging may be formed in other portions.
The caps 31a, 31b, and 31c also have a function of capping the
ink-jet heads 120a, 120b, and 120c and receiving inks from the
respective nozzles so as to prevent the nozzles from discharging
excessive amounts of inks when an operation (pressuring/restoring
operation) of keeping the ink-jet heads 120a, 120b, and 120c in a
normal state is to be performed by periodically pressuring or
circulating inks from the ink supply side to the ink-jet heads
120a, 120b, and 120c using an ink pressuring motor (not shown) and
forcibly discharging bubbles and dust, which cause discharge
failures, from the nozzles.
Reference numerals 32a, 32b, and 32c denote blades for wiping the
nozzle surfaces. Each blade preferably has water absorption
property. As shown in FIG. 14, with the operation of the restoring
unit 30 in the X direction, the blades 32a, 32b, and 32c wipe off
the ink adhering to the nozzle surfaces of the ink-jet heads 120a,
120b, and 120c or ink mists which are produced upon discharging of
inks and adhere to the nozzle surfaces.
Reference numeral 33 denotes a restoring pail disposed below the
caps 31a, 31b, and 31c and the blades 32a, 32b, and 32c to prevent
inks leaking from the caps or cap and blade cleaning solutions (to
be described later) from leaking into the apparatus. Inks and
cleaning solutions stored in the restoring pail 33 are guided into
a drainage bath 37. The restoring pail 33 is designed to operate
integrally with the caps 31a, 31b, and 31c and the blades 32a, 32b,
and 32c. When a capping operation in the Z direction and a wiping
operation in the X direction are performed, the restoring pail 33
operates in the same manner as the caps 31a, 31b, and 31c, and the
blades 32a, 32b, and 32c.
Reference numerals 34a, 34b, and 34c denote open valves. One end of
each open valve communicates with a corresponding one of the caps
31a, 31b, and 31c via tubes. The other end of each open valve is
set at the atmospheric pressure. The caps 31a, 31b, and 31c are
made of rubber and pressed against the respective heads with a
force of about 1 kgf or more, and then the volume of each cap
decreases. The internal pressure of each cap exceeds the
atmospheric pressure. As a result, an ink in each nozzle is pushed
into each ink-jet head, causing a discharge failure. The open
valves 34a, 34b, and 34c are arranged to prevent such a phenomenon.
Each open valve is closed in a normal operation. Before a capping
operation, each open valve is opened. By keeping each open valve
closed after a capping operation, the inside of each cap can be
kept at the atmospheric pressure.
Reference numeral 35 denotes a cap suction pump for sucking an ink
stored in each cap in a pressuring/restoring operation, and sucking
an ink pre-discharged into each cap. The cap suction pumps 35 are
respectively connected to the caps 31a, 31b, and 31c via tubes. The
sucked inks are discharged into the drainage bath 37.
Reference numeral 36 denotes blade suction pumps 36 for sucking
water absorbed by the blades 32a, 32b, and 32c each made of a
material having water absorption property, and sucking inks
absorbed in a wiping operation. The blade suction pumps 36 are
respectively connected to the blades 32a, 32b, and 32c via tubes.
The absorbed water and inks are discharged into the drainage bath
37. The water and inks discharged into the drainage bath 37 are
discharged outside the apparatus altogether.
Reference numeral 38 (see FIG. 12) denotes a washing water tank for
storing washing water for washing the caps 31a, 31b, and 31c and
the blades 32a, 32b, and 32c. When a washing water supply valve 39
is opened, washing water is sprayed from each washing water supply
nozzle 40. Referring to FIG. 11, these washing water supply nozzles
40 are positioned immediately above the restoring unit 30 when the
ink-jet head IJH (120a, 120b, and 120c) completely colors the glass
substrate 1.
Reference numeral 41 (see FIG. 12) denotes a washing water
replenishment valve for replenish washing water into the washing
water tank 38. When a washing water residue detection sensor 42
detects that the amount of washing water in the washing water tank
38 becomes small, the washing water replenishment valve 41 is kept
open for a predetermined period of time to replenish washing water
into the washing water tank 38. As this washing water, distilled
water obtained by removing impurities from tap water is used.
FIG. 15 shows the structure of the ink-jet head IJH for discharging
an ink onto the resin composition layer 3. Since these three
ink-jet heads 120a, 120b, and 120c have the same structure, FIG. 15
shows the structure of one of them as a representative.
Referring to FIG. 15, the ink-jet head IJH mainly comprises a
heater board 104 as a board on which a plurality of heaters 102 for
heating an ink are formed, and a ceiling plate 106 mounted on the
heater board 104. A plurality of discharging openings 108 are
formed in the ceiling plate 106. Tunnel-like fluid passages 110
communicating with the discharging openings 108 are formed
therebehind. The respective fluid passages 110 are isolated from
the adjacent fluid passages via partition walls 112. The respective
fluid passages 110 are commonly connected to one ink chamber 114 at
the rear side of the fluid passages. An ink is supplied to the ink
chamber 114 via an ink inlet 117. This ink is supplied from the ink
chamber 114 to each fluid passage 110.
The heater board 104 and the ceiling plate 106 are positioned such
that the position of each heater 102 coincides with that of a
corresponding fluid passage 110, and are assembled into the state
shown in FIG. 15. Although FIG. 15 shows only two heaters 102, the
heater 102 is arranged in correspondence with each fluid passage
110. When a predetermined driving signal is supplied to the heater
102 in the assembled state shown in FIG. 15, an ink above the
heater 102 is boiled to produce a bubble, and the ink is pushed and
discharged from the discharging opening 108 upon volume expansion
of the ink.
FIG. 16 is a block diagram showing the arrangement of the color
filter manufacturing apparatus of this embodiment.
Referring to FIG. 16, X- and Y-direction driving motors 56 and 58
for driving the X-Y table 22 in the X and Y directions are
connected to a CPU 50 for controlling the overall operation of the
manufacturing apparatus via X and Y motor driving circuits 52 and
54. A Z-direction driving motor 59 for driving the restoring unit
30 in the Z direction is connected to the CPU 50 via a Z motor
driving circuit 55.
The ink-jet head IJH is also connected to the CPU 50 via a head
driving circuit 60. Furthermore, X and Y encoders 62 and 64 for
detecting the position of the X-Y table 22 is connected to the CPU
50. With this arrangement, position information of the X-Y table 22
is input to the CPU 50. In addition, a control program in a program
memory 66 is input to the CPU 50. The CPU 50 moves the X-Y table 22
in accordance with this control program and position information
from the X and Y encoders 62 and 64. With this operation, a desired
grating frame (pixel) on the glass substrate 1 is brought to a
position below the ink-jet head IJH, and an ink having a desired
color is discharged into the pixel to color it, thereby coloring
the glass substrate 1. A color filter is manufactured by performing
this operation for each pixel. Every time coloring of one glass
substrate 1 is completed, the restoring unit 30 mounted on an end
portion of the X-Y stage 22 is moved to a position immediately
below the ink-jet head IJH, and the blades 32a, 32b, and 32c are
moved in the X direction by the X-direction driving motor 56 to
perform a wiping operation. In addition, the caps 31a, 31b, and 31c
are moved in the Z direction by the Z-direction driving motor 59 to
perform a pre-discharging operation. Meanwhile, the colored glass
substrate 1 is replaced with a new glass substrate 1 by a substrate
convey unit (not shown).
The operation of the color filter manufacturing apparatus of this
embodiment will be described next with reference to FIG. 17.
In step S1, inks are discharged from the ink-jet head IJH onto the
glass substrate 1 to color one glass substrate 1. When coloring of
one substrate is completed, the X-Y stage 22 is operated to move
the restoring unit 30 to the position of each washing water supply
nozzle 40, and washing water is sprayed against the blades 32a,
32b, and 32c, thereby washing the blades (step S2). The X-Y stage
22 is then moved to move the restoring unit 30 to the position of
the ink-jet head IJH (step S3). If it is determined in step S4 that
the number of colored substrates is less than a predetermined
number, a normal wiping operation is performed by using the blades
32a, 32b, and 32c to wipe off ink mists adhering to the nozzle
surfaces (step S5). If it is determined in step S4 that not less
than a predetermined number of substrates are colored, a
pressuring/restoring operation is performed to remove an ink with
increased viscosity in each nozzle and bubbles in the ink chamber
(step S6). In this embodiment, every time 30 glass substrates are
colored, a pressuring/restoring operation is performed. This
pressuring/restoring operation is performed only to discard inks
without using them for a coloring operation, and requires an
increase in the number of steps, demanding a corresponding period
of time. For this reason, the number of times this operation is
performed is preferably minimized.
When a pressuring/restoring operation is performed, an ink adheres
to the nozzle surfaces. For this reason, a wiping operation for a
pressuring operation is performed afterward (step S7). Since the
ink discharged from the nozzles adheres to the caps in the
pressuring/restoring operation (step S6), a cap washing operation
is performed (step S8). It is checked whether the coloring
operation is terminated for maintenance of the apparatus or the
like (step S9). If it is determined that the coloring operation is
terminated, the capping operation and the like are terminated (step
S12) to terminate the coloring operation. If it is determined that
the coloring operation is continued, the ink-jet heads 120a, 120b,
and 120c are capped, and each ink-jet head performs a
pre-discharging operation to discharge a predetermined number of
inks (step S10). Thereafter, a cap washing operation is performed
to wash away the inks pre-discharged and adhering to the caps (step
S11). While these restoring operations are performed, the colored
substrate is replaced with a new substrate, and the next coloring
operation is performed. This process is repeated.
Characteristic features of the present invention in coloring a
glass substrate will be described next with reference to FIGS. 18
and 19.
Each of the heads 120a, 120b, and 120c of the ink-jet head IJH in
FIG. 18 has 512 effective nozzles, and a nozzle pitch of 70.5
.mu.m. That is, each ink-jet head has a resolution of 360 dpi. As
shown in FIG. 9, according to the color filter of this embodiment,
the pixels of each color are arranged at a pitch of 300 .mu.m.
Since the pixel pitch is different from the nozzle pitch of the
ink-jet head IJH, every five nozzles of the ink-jet head IJH are
used. That is, as shown in FIG. 18, only 120 nozzles of the 512
nozzles of the ink-jet head IJH are used. For this reason, the
ink-jet head IJH is tilted at 31.672.degree., as shown in FIG. 18.
FIG. 19 shows the positional relationship between the pixels of the
respective colors and the nozzles of the ink-jet head IJH. Of the
nozzles 108 of each of the ink-jet heads 120a, 120b, and 120c, only
every five nozzles indicated by the solid lines are located above
the pixels of the corresponding colors. The remaining nozzles
indicated by the broken lines are located outside the pixels of the
corresponding colors. That is, the nozzles indicated by the solid
lines are substantially arranged at a pitch of 300 .mu.m in the Y
direction. Since the nozzles of each of the ink-jet heads 120a,
120b, and 120c are arranged at 70.5-.mu.m intervals, every five
nozzles of the nozzles indicated by the broken lines are also
arranged at a pitch of 300 .mu.m in the Y direction.
The process of manufacturing a color filter having an effective
display area like the one shown in FIG. 10, i.e., coloring pixels
of the respective colors like those shown in FIG. 9, by using the
ink-jet head IJH having the nozzles 108 arranged in the above
manner will be described next. As described above, the ink-jet head
IJH is positioned at an angle of 31.672.degree. with respect to the
glass substrate 1. As shown in FIG. 19, the respective ink-jet
heads are shifted from each other by 100 .mu.m in the Y direction
such that every five nozzles of each ink-jet head IJH are
positioned above corresponding pixels. In this case, the ink-jet
heads 120a, 120b, an 120c have the same structure regardless of the
colors of inks. In the actual manufacturing apparatus, the ink-jet
heads are fixed, and a glass substrate is moved. However, FIG. 18
shows a state wherein the glass substrate is fixed, and the ink-jet
heads are moved. Since the ink-jet heads and the glass substrate
relatively move, it makes no difference whether the glass substrate
is fixed or moved.
As shown in FIG. 18, the width of a portion at which each head can
color by one scanning operation corresponds to 102 pixels, which
correspond to 1/5 the 512 nozzles. The distance between the centers
of the pixels on the two ends is 30.3 mm. That is, the entire
effective display area of the glass substrate cannot be colored by
one scanning operation in the X direction. For this reason, as
shown in FIG. 18, after the ink-jet head IJH is scanned on the
glass substrate once in the X direction, the ink-jet head is
relatively moved by 30.6 mm in the Y direction, and is scanned
again in the X direction. This operation is repeated once to color
the entire effective display area of the glass substrate.
Meanwhile, each of the ink-jet heads 120a, 120b, and 120c is
controlled such that only every five nozzles are always used.
At this time, as shown in FIG. 20, with regard to one pixel, a
plurality of inks are continuously discharged from the same nozzle
to cover the entire area of a frame of the black matrix 2 such that
the center of each ink falls within the frame.
In a pre-discharging operation in step S10 in FIG. 17, which is
performed before coloring of one glass substrate is started, the
ink-jet head IJH is normally controlled to cause only the nozzles
used for a coloring operation to perform a pre-discharging
operation. In this embodiment, since a pressuring/restoring
operation of discharging the ink from all the nozzles is performed
every time 30 glass substrates are colored, the nozzles which are
not used for a coloring operation are not used at all during such
coloring operations. If a nozzle is not used for a certain period
of time, an ink may solidify and clog up the nozzle. In this case,
the nozzle may not be restored by a pressuring/restoring operation.
For this reason, in this embodiment, all the nozzles are caused to
perform a pre-discharging operation every time 10 substrates are
colored.
With this operation, a pressuring/restoring operation which
consumes an ink can be performed at longer intervals. In addition,
since only the nozzles to be used are caused to perform a
discharging operation in a normal operation, the amount of ink
consumed in restoring operations can be minimized. Furthermore, by
decreasing the number of times a pressuring/restoring operation is
performed, the number of substrates colored per unit time can be
increased. By making use of the nozzles which are not used for
coloring operations in this manner, even if the service lives of
every five nozzles used for coloring operations expire, this
ink-jet head can be used again by arranging the remaining nozzles
to allow them to be used for coloring operations.
Second Embodiment
FIGS. 21 and 22 are views each showing the nozzle arrangement of an
ink-jet head IJH in a color filter manufacturing apparatus
according to the second embodiment of the present invention.
FIG. 21 shows the nozzle arrangement constituted by two arrays of
nozzles. The nozzles are arranged at a pitch of 70.5 .mu.m, i.e., a
resolution of 360 dpi, in the longitudinal direction of the
head.
When this head is used for coloring of a color filter having pixels
of each color arranged at a pitch of 300 .mu.m as in FIG. 9, every
six nozzles indicated by the thick solid lines are used, and the
head is tilted at 44.829.degree..
FIG. 22 shows the nozzle arrangement constituted by three arrays of
nozzles. The nozzles are arranged at a pitch of 70.5 .mu.m, i.e., a
resolution of 360 dpi, in the longitudinal direction of the
head.
When this head is used for coloring of a color filter having pixels
of each color arranged at a pitch of 300 .mu.m as in FIG. 9, every
six nozzles indicated by the thick solid lines are used, and the
head is tilted at 44.829.degree., as in the case shown in FIG.
21.
With the ink-jet heads having the above nozzle arrangements as
well, the same effects as described above can be obtained by
performing discharge control in the same manner as in the above
embodiment.
Third Embodiment
A color filter manufacturing apparatus of the third embodiment has
the same arrangement as that of the first embodiment. The third
embodiment is characterized by its control method. For this reason,
a description of the apparatus will be omitted, and the third
embodiment will be described with reference to the drawings used to
described the first embodiment.
As shown in FIG. 18, the width of a portion which each head can
color by one scanning operation corresponds to 102 pixels, which
correspond to 1/5 the 512 nozzles. The distance between the centers
of the pixels on the two ends is 30.3 mm. That is, the entire
effective display area of the glass substrate cannot be colored by
one scanning operation in the X direction. For this reason, as
shown in FIG. 18, after an ink-jet head IJH is scanned on the glass
substrate once in the X direction, the ink-jet head is relatively
moved by 30.6 mm in the Y direction to position the nozzles used
for the previous scanning operation above the corresponding pixels
so as to discharge the ink from the same nozzles as those used in
the previous scanning operation. Meanwhile, the ink-jet head is
scanned again in the X direction. As shown in FIG. 18, after the
second scanning operation, a 28-pixel portion of each color is left
uncolored. The ink-jet head IJH is therefore relatively moved in
the Y direction to position the nozzles used in the previous
scanning operation above the corresponding pixels, and each head is
scanned again in the X direction to color the entire effective
display area of the glass substrate by using 28 nozzles of the
nozzles used in the previous scanning operation. An X-Y stage 22 is
moved to move each head in the Y direction immediately after
coloring of the last pixel in one scanning operation so as to
change the position of each head relative to the glass substrate
between scanning operations. Meanwhile, each of ink-jet heads 120a,
120b, and 120c is controlled to always use only every five
nozzles.
At this time, as shown in FIG. 20, with regard to one pixel, a
plurality of inks are continuously discharged from the same nozzle
to cover the entire area of a frame of the black matrix 2 such that
the center of each ink falls within the frame.
As described above, the nozzles which are not used in the previous
scanning operation are not used in the succeeding scanning
operation, but the nozzles which are used in the previous scanning
operation are always used in the succeeding scanning operation. For
this reason, all the nozzles used for a coloring operation are in
an idle state for only a short period of time, and hence each head
is kept in a state in which it can stably discharge an ink.
Therefore, a high-quality coloring operation can always be
performed. In addition, since the heads need not be relatively
moved to the positions of the caps or portions for receiving
pre-discharged inks so as to perform a pre-discharging operation,
the coloring time per substrate can be shortened, and the
production per unit time increases, realizing a reduction in the
cost of a color filter.
With the ink-jet heads having the above nozzle arrangements shown
in FIGS. 21 and 22 as well, the same effects as described above can
be obtained by performing discharge control in the same manner as
in this embodiment.
In this embodiment, a coloring operation is performed by using the
maximum number of nozzles which can be used in the first to sixth
scanning operations, and using only about 1/4 the nozzles in the
remaining scanning operations. However, the same effects as
described above can be obtained by using any combination of the
numbers of nozzles to be used as long as the nozzles which are used
in the previous scanning operation are always used in the
succeeding scanning operation, and the number of nozzles used is
decreased.
Fourth Embodiment
A color filter manufacturing apparatus of the fourth embodiment is
the same as that of the first embodiment except for the numbers of
heads and nozzles. Only the differences between the fourth and
first embodiments will be described below.
As shown in FIG. 23, the maximum width of a portion at which each
head can color by one scanning operation corresponds to 272 pixels,
which correspond to 1/5 the 1,360 nozzles. The distance between the
centers of the pixels on the two ends is 81.6 mm. That is, the
entire effective display area of the glass substrate cannot be
colored by one scanning operation in the X direction. For this
reason, as shown in FIG. 23, after an ink-jet head IJH is scanned
on the glass substrate once in the X direction (scan 1), the
ink-jet head is relatively moved by 81.6 mm in the Y direction
(step 1) to position the nozzles used for the previous scanning
operation above the corresponding pixels so as to discharge the ink
from the same nozzles as those used in the previous scanning
operation. Meanwhile, the ink-jet head is scanned again in the X
direction (scan 2). As shown in FIG. 23, after the second scanning
operation (scan 2), 96-pixel portion of each color is left
uncolored. The ink-jet head IJH is therefore relatively moved in
the Y direction (step 2) to position the nozzles used in the
previous scanning operation (scan 2) above the corresponding
pixels, and each head is scanned again in the X direction (scan 3)
to color the entire effective display area of the glass substrate
by using 96 nozzles of the nozzles used in the previous scanning
operation (scan 2). An X-Y stage 22 is moved to move each head in
the Y direction immediately after coloring of the last pixel in one
scanning operation so as to change the position of each head
relative to the glass substrate between scanning operations.
Meanwhile, each ink-jet head IJH is controlled to always use only
every five nozzles.
Consider a nozzle 200 on the left end of an ink-jet head 120a in
the case shown in FIG. 23. A thick solid line 201 indicates the
distance the nozzle 200 has moved without discharging any ink
between the first scanning operation (scan 1) and the second
scanning operation (scan 2). The length of this thick solid line
can be calculated as follows, provided that the distance between
the heads on the two ends in the scanning direction is 48 mm:
(95.598.times.sin 31.672.degree.+48).times.2+81.6=277.989 (mm)
The case shown in FIG. 24 in the fourth embodiment of the present
invention will be described next.
In the case shown in FIG. 24, the numbers of nozzles used in the
respective scanning operations (including the last scanning
operation) are set to be almost the same. That is, all the nozzles
are divided into groups including almost the same number of nozzles
such that 214 nozzles are used for the first scanning operation
(scan 1); 213 nozzles, for the second scanning operation (scan 2);
and 213 nozzles, for the third scanning operation (scan 3).
Consider a nozzle 202 (to be used to discharge an ink) on the left
end of the ink-jet head 120a, as in the case shown in FIG. 23. A
thick solid line 203 indicates the distance the nozzle 202 has
moved without discharging any ink between the first scanning
operation (scan 1) and the second scanning operation (scan 2). The
length of this thick solid line can be calculated as follows,
provided that the distance between the heads on the two ends in the
scanning direction is 48 mm as in the case shown in FIG. 23:
(75.153.times.sin 31.672.degree.+48).times.2+64.2=239.119 (mm)
As is apparent from this calculation, the distance each ink
discharging nozzle moves without discharging any ink between
scanning operations in the case shown in FIG. 24 is shorter than
that in the case shown in FIG. 23. This means that the time during
which each nozzle discharges no ink is shortened. If an ink in a
given nozzle is kept in contact with air without being discharged,
volatile components in the ink evaporate to increase the viscosity
of the ink. As a result, a discharge failure, i.e., inability to
discharge the ink, or twisting, i.e., inability to discharge the
ink straight, may occur. In order to prevent such a phenomenon, it
is important to minimize the time during which the ink discharging
nozzle is caused to stand without discharging any ink.
Since the time during which the ink discharging nozzle is in
contact with air between scanning operations is shorter than that
in the case shown in FIG. 23, a discharge failure and twisting
occur less frequently. That is, there is provided a color filter
manufacturing apparatus which stabilizes the discharging operation
of each ink-jet head, and suppresses the occurrence of defective
products, thereby attaining an increase in yield.
With the ink-jet heads having the above nozzle arrangements shown
in FIGS. 21 and 22 as well, the same effects as described above can
be obtained by performing discharge control in the same manner as
in this embodiment.
In each of the cases shown in FIGS. 23 and 24, one screen is
colored by performing a scanning operation three times. However,
the present invention is not limited to this. A scanning operation
may be performed four or more times. This embodiment is especially
effective for a case wherein an area which can be colored by one
scanning operation is slightly less than a fraction of an integer
of one screen, and one screen is colored by three or more scanning
operations.
Fifth Embodiment
Each ink-jet head used in the fifth embodiment has nozzles arranged
at a pitch of 70.5 .mu.m. The nozzle array is tilted in a scanning
direction, and for example, every six nozzles are used to color
pixels of the same color. A color filter manufactured by the
apparatus of this embodiment has the same color pattern as that
shown in FIG. 9.
FIG. 25 shows the arrangement of the color filter manufacturing
apparatus of the fifth embodiment. Reference numeral 301 denotes a
drawing image (the pixel array pattern of a color filter) which is
data indicating the relative position relationship between ink dots
to be formed on a substrate 1; and 302, a nozzle switching signal
for designating a switching operation for nozzles corresponding to
the respective pixels of the color filter. A nozzle group switching
method will be described in detail with reference to FIGS. 25 and
1. Assume that the second, seventh, and twelfth nozzle groups,
counted from the right end, are being used. In this case,
sequential use of nozzle groups is easy to perform. That is, the
third, eighth, and thirteenth nozzle groups are used for the next
operation, and the fourth, ninth, and fourteenth nozzle groups for
the still next operation. However, another switching method may be
used. In addition, a nozzle group switching operation is performed
when the service lives of the currently used nozzles expire. For
example, the service life of each nozzle is based on the operating
time of one nozzle group. When the operating time of one nozzle
group reaches a predetermined time, it is determined that the
service life has expired. Reference numeral 303 denotes a drawing
data generator for generating drawing data as data indicating the
absolute position of each ink dot on a substrate by relating each
pixel on the substrate with a corresponding nozzle in accordance
with a nozzle switching signal. In this case, upon switching of
nozzles, a change in the position of each nozzle after the nozzle
switching operation is calculated from known data associated with a
nozzle arrangement, and the position of a stage 308 is changed in
accordance with the calculated change in forming each ink dot
before and after the nozzle switching operation. Reference numeral
304 denotes a driver for driving an ink-jet head 305 and feeders
306 and 307 in accordance with the drawing data to form ink dots
corresponding to the drawing data on the substrate 1. The ink-jet
head 305 includes a red head 305a for discharging a red ink, a
green head 305b for discharging a green ink, and a blue head 305c
for discharging a blue ink. The feeders 306 and 307 respectively
move the position of the stage 308 in the X and Y directions in
accordance with a signal from the driver 304. The stage 308 holds
the substrate 1 to be colored. With the above arrangement, a
drawing pattern 310 corresponding to the drawing image 301 is
formed on the substrate 1.
In this embodiment, a change in the positional relationship between
a substrate and each drawing head, which occurs upon nozzle
switching and corresponds to an offset amount of each nozzle
position, is estimated from known data associated with a nozzle
arrangement. However, the positional relationship between ink dots
actually formed by the respective nozzles may be measured by using
an image processing apparatus.
In many actual configurations, the nozzle switching signal 302 and
the drawing data generator 303 are realized as the function of one
or a plurality of computers connected to each other.
In this embodiment, the means for switching nozzle groups to be
used corresponds to the nozzle switching signal 302 and the drawing
data generator 303, the means for estimating or measuring a change
in the positional relationship between the substrate 1 (pixel) and
each nozzle of each ink-jet head, which corresponds to an offset
amount of each nozzle, corresponds to the drawing data generator
303, and the means for changing the positional relationship between
the substrate 1 and each ink-jet head (nozzle) corresponds to the
drawing data generator 303, the driver 304, and the feeders 306 and
307.
Sixth Embodiment
FIG. 26 shows the arrangement of a color filter manufacturing
apparatus of the sixth embodiment. In the fifth embodiment,
detection of a defective nozzle and nozzle switching are externally
performed. In contrast to this, in this embodiment, a discharge
count calculator 311 is used to calculate the number of times each
nozzle discharges an ink on the basis of the operating time of the
nozzle and the number of times the nozzle discharges the ink per
unit time, thereby estimating a defective nozzle and performing
nozzle switching.
In this embodiment, a defective nozzle is estimated by calculating
the number of times each nozzle discharges an ink on the basis of
the operating time of the nozzle and the number of times the nozzle
discharges the ink per unit time. However, the number of times each
nozzle discharges an ink may be directly measured, or an image
processing apparatus or the like may be used to detect a defective
nozzle on the basis of the state of each ink dot.
In this embodiment, since nozzle switching is automatically
performed, labor saving can be easily realized, and a continuous
operation can be performed for a long period of time, as compared
with the fifth embodiment.
Seventh Embodiment
FIG. 27 shows the arrangement of a color filter manufacturing
apparatus of the seventh embodiment. In this embodiment, the
temperature distribution of each nozzle of each ink-jet head is
measured, and nozzle switching is performed in accordance with the
measurement result.
In the color filter manufacturing apparatus, the layouts of ink
dots drawn in coloring operations are identical to each other, and
a change in the temperature of each nozzle in use exhibits almost a
constant pattern. In addition, temperature environments such as
external temperatures are almost constant in many instances. For
this reason, the temperature of each nozzle can be estimated from
the operating time of the nozzle. In this embodiment, the
temperature of each nozzle is actually measured to perform nozzle
switching. However, almost the same effect can be obtained by using
a method of performing nozzle switching at predetermined intervals
without actually measuring the temperature of each nozzle.
In the above embodiments, since a rise in the temperature of each
nozzle is suppressed, a discharge failure due to scorching of an
ink or the like can be prevented. In addition, since an idle time
is set for each nozzle after a predetermined operating time, the
service life of the nozzle is prolonged.
In the above embodiments, the black matrix 2 is formed on the
substrate 1. However, the present invention is not limited to this.
For example, in FIGS. 3A to 3F, the black matrix 2 may be formed on
the other substrate which opposes the glass substrate 1. In this
case, an ink is discharged into the frame of each portion 5 having
no affinity for an ink in FIG. 2D.
In the above embodiments, as each ink-jet head, a bubble-jet type
ink-jet head is used, in which an ink on the heater 102 is boiled
to produce a bubble, and the ink is pushed and discharged from the
discharging opening 108 upon volume expansion of the bubble.
However, the present invention is not limited to this. For example,
an ink-jet head using a piezoelectric element may be used.
According to the above description, the present invention is
applied to the print apparatus of the system, among various ink-jet
recording systems, which has a means (e.g., an electrothermal
converter or laser light) for generating heat energy as energy used
to discharge an ink, and changes the state of an ink by using the
heat energy. According to this system, a high-density,
high-definition recording operation can be realized.
As for the typical structure and principle, it is preferable that
the basic structure disclosed in, for example, U.S. Pat. No.
4,723,129 or U.S. Pat. No. 4,740,796 is employed. The above method
can be adapted to both a so-called on-demand type apparatus and a
continuous type apparatus. In particular, a satisfactory effect can
be obtained when the on-demand type apparatus is employed because
of the structure arranged in such a manner that one or more drive
signals, which rapidly raise the temperature of an electrothermal
converter disposed to face a sheet or a fluid passage which holds
the fluid (ink) to a level higher than levels at which film boiling
takes place are applied to the electrothermal converter in
accordance with recording information so as to generate heat energy
in the electrothermal converter and to cause the heat effecting
surface of the recording head to take place film boiling so that
bubbles can be formed in the fluid (ink) to correspond to the one
or more drive signals. The enlargement/contraction of the bubble
will cause the fluid (ink) to be discharged through a discharging
opening so that one or more inks are formed. If a pulse shape drive
signal is employed, the bubble can be enlarged/contracted
immediately and properly, causing a further preferred effect to be
obtained because the fluid (ink) can be discharged while revealing
excellent responsibility.
It is preferable that a pulse drive signal disclosed in U.S. Pat.
No. 4,463,359 or U.S. Pat. No. 4,345,262 is employed. If conditions
disclosed in U.S. Pat. No. 4,313,124 which is an invention relating
to the temperature rising ratio at the heat effecting surface are
employed, a satisfactory recording result can be obtained.
As an alternative to the structure (linear fluid passage or
perpendicular fluid passage) of the recording head disclosed in
each of the above inventions and having an arrangement that
discharge ports, fluid passages and electrothermal converters are
combined, a structure having an arrangement that the heat effecting
surface is disposed in a bent region and disclosed in U.S. Pat. No.
4,558,333 or U.S. Pat. No. 4,459,600 may be employed. In addition,
the following structures may be employed: a structure having an
arrangement that a common slit is formed to serve as a discharge
section of a plurality of electrothermal converters and disclosed
in Japanese Patent Laid-Open No. 59-123670; and a structure
disclosed in Japanese Patent Laid-Open No. 59-138461 in which an
opening for absorbing pressure waves of heat energy is disposed to
correspond to the discharge section.
Furthermore, as a recording head of the full line type having a
length corresponding to the maximum width of a recording medium
which can be recorded by the recording apparatus, either the
construction which satisfies its length by a combination of a
plurality of recording heads as disclosed in the above
specifications or the construction as a single full line type
recording head which has integrally been formed can be used.
In addition, the invention is effective for a recording head of the
freely exchangeable chip type which enables electrical connection
to the recording apparatus main body or supply of ink from the main
device by being mounted onto the apparatus main body, or for the
case by use of a recording head of the cartridge type provided
integrally on the recording head itself.
It is preferred to additionally employ the recording head restoring
means and the auxiliary means provided as the component of the
present invention because the effect of the present invention can
be further stabled. Specifically, it is preferable to employ a
recording head capping means, a cleaning means, a pressurizing or
suction means, an electrothermal converter, an another heating
element or a sub-heating means constituted by combining them and a
sub-emitting mode in which an emitting is performed independently
from the recording emitting in order to stably perform the
recording operation.
Although a fluid ink is employed in the above embodiments of the
present invention, an ink which is solidified at the room
temperature or lower, or an ink which is softened or liquified at
the room temperature may be used. That is, any ink which is
liquified when a recording signal is supplied may be used.
Furthermore, an ink which is solidified when it is caused to stand,
and liquified when heat energy is supplied in accordance with a
recording signal can be adapted to the present invention to
positively prevent a temperature rise caused by heat energy by
utilizing the temperature rise as energy of state transition from
the solid state to the liquid state or to prevent ink evaporation.
In any case, an ink which is liquified when heat energy is supplied
in accordance with a recording signal so as to be discharged in the
form of fluid ink, or an ink which is liquified only after heat
energy is supplied, e.g., an ink which starts to solidify when it
reaches a recording medium, can be adapted to the present
invention. In the above case, the ink may be of a type which is
held as fluid or solid material in a recess of a porous sheet or a
through hole at a position to face the electrothermal converter as
disclosed in Japanese Patent Laid-Open No. 54-56847 or Japanese
Patent Laid-Open No. 60-71260. It is the most preferred way for the
ink to be adapted to the above film boiling method.
As has been described above, according to the present invention,
since an ink-jet head used in a general printer or an ink-jet head
having a simple modification is used as an ink-jet head used to
manufacture a color filter, a reduction in the cost of an ink-jet
head can be attained. A reduction in the cost of a manufacturing
apparatus can therefore be attained. In addition, the manufacturing
cost per color filter can be reduced.
Since the amount of each ink used per color filter can be reduced,
a more inexpensive color filter, a display device using the color
filter, and an apparatus using the display device can be
provided.
When one glass substrate is to be colored by performing a plurality
of scanning operations, the discharging operation of each ink-jet
head can be stabilized, and the occurrence of defective products
can be suppressed. In addition, the color time required for one
glass substrate can be shortened to increase the production per
unit time. Therefore, a color filter manufacturing method and
apparatus which can manufacture a color filter at a lower cost can
be provided.
There is provided a color filter manufacturing apparatus which can
stabilize the discharging operations of ink-jet heads, each having
discharging nozzles arranged at a pitch matching with a pixel
pitch, and suppress the occurrence of defective products to attain
an increase in yield by shortening the idle time between scanning
operations, during which each discharging nozzle of each ink-jet
head discharges no ink, when the ink-jet heads are to be relatively
scanned a plurality of numbers of times to color one substrate.
In addition, in each ink-jet head, nozzles to be used can be
switched. Even if a failure occurs in a nozzle in use, the
manufacture of a color filter can be continued by using another
nozzle.
Furthermore, since the service life of each ink-jet head is
prolonged as compared with a conventional ink-jet head used for a
color filter, the frequency in replacing ink-jet heads
decreases.
Moreover, the size and color density of each ink dot can be kept
constant. According to the present invention, since a rise in the
temperature of each nozzle is suppressed, a discharge failure due
to scorching of an ink or the like can be prevented. In addition,
since an idle time is set for each nozzle after a predetermined
operating time, the service life of the nozzle is prolonged.
The present invention is not limited to the above embodiments and
various changes and modifications can be made within the spirit and
scope of the present invention. Therefore, to apprise the public of
the scope of the present invention the following claims are
made.
* * * * *